I've been writing about the company since it started out just
under two years ago and I'm not surprised — in fact, I would have
thought it would be worth more.

The company's smart tech blows away top government cyber security
agents. It's working with huge corporates like Virgin Trains
despite just starting out in September 2013. And it was funded by
Mike Lynch, the man
dubbed Britain's answer to Bill Gates.

Darktrace's big idea is that instead of doing cyber security like
a medieval fortress by erecting a big wall to keep people out,
it's better to do it like espionage — track people who break in
to find out what they're after, who they are, and how they got
in.

Hackers are getting more sophisticated, and it's getting more and
more futile to simply expect you can keep them out — as
high-profile hacks on the likes of Ashley
Madison and
Sony show.

Darktrace's system picks up on strange activity in
companies' networks by monitoring what workers normally
do to spot out of the ordinary behaviour.

All of this is fed back into a machine learning algorithm, which
means Darktrace's technology gets smarter the longer it's
running. The company likens it to an immune system that grows as
it's exposed to more illnesses.

Darktrace's technology is based on mathematical research carried
out at Cambridge University, and when France first saw it, he
quit GCHQ after a 30 year career there, just so he could run the
company — that's how blown away he was. (France has since been
replaced as CEO but still sits on the company's board.)

France isn't the only person to have such a strong reaction — the
company is jam-packed with former government cyber security
agents and spies.

It's smart money too. Mike Lynch, the founder of Cambridge
software company Autonomy, put $20 million (£12.8 million) into
the company back when it was just a clever maths equation. That's
a huge initial investment, and he's continued to fund Darktrace
since.

Lynch has become notorious in recent years for his
very public spat with HP over the $11.7 billion (£7.5
billion) sale of Autonomy back in 2011. HP was forced to
writedown $8.8 billion (£5.6 billion) on that deal.

Finally, big companies are clearly impressed with Darktrace's
technology. While many of the companies that use Darktrace don't
want to shout about it,
known customers include power company Drax, Virgin Trains and
BT. Darktrace's tech is particularly useful in complex
networks — the more complexity, the greater chance of holes in
the security system.

Remember, this company is only 23-months-old. Darktrace is
already turning heads in the NSA and GCHQ, raising a tonne of
money, and doing business with some of Britain's biggest
companies. That's why it's worth $100 million — and why it could
be worth much more.